Add WebKit prefix to MediaSource,SourceBuffer, and SourceBufferList objects.

Source/modules/mediasource/WebKitMediaSource.idl

Index: Source/modules/mediasource/WebKitMediaSource.idl
diff --git a/Source/modules/mediasource/MediaSource.idl b/Source/modules/mediasource/WebKitMediaSource.idl
similarity index 87%
rename from Source/modules/mediasource/MediaSource.idl
rename to Source/modules/mediasource/WebKitMediaSource.idl
index 6550c8b4a222ca0754435940819084dbb0f02a9a..573548b1fd2527d0fafdb51debdff885a5e14ba0 100644
--- a/Source/modules/mediasource/MediaSource.idl
+++ b/Source/modules/mediasource/WebKitMediaSource.idl
@@ -30,22 +30,22 @@
  
 [
     NoInterfaceObject,
-    EnabledAtRuntime=mediaSource,
+    EnabledAtRuntime=webKitMediaSource,
     ActiveDOMObject,
     EventTarget,
     Constructor,
     CallWith=ScriptExecutionContext
-] interface MediaSource {
+] interface WebKitMediaSource {
     // All the source buffers created by this object.
-    readonly attribute SourceBufferList sourceBuffers;
+    readonly attribute WebKitSourceBufferList sourceBuffers;
 
     // Subset of sourceBuffers that provide data for the selected/enabled tracks.
-    readonly attribute SourceBufferList activeSourceBuffers;
+    readonly attribute WebKitSourceBufferList activeSourceBuffers;
 
     [SetterRaisesException] attribute double duration;
 
-    [RaisesException] SourceBuffer addSourceBuffer(DOMString type);
-    [RaisesException] void removeSourceBuffer(SourceBuffer buffer);
+    [RaisesException] WebKitSourceBuffer addSourceBuffer(DOMString type);
+    [RaisesException] void removeSourceBuffer(WebKitSourceBuffer buffer);
 
     readonly attribute DOMString readyState;